Define the following :

1. Ductility. Ans. The ability of metals to be drawn into thin wires is called as ductility.

2. Malleability. Ans. The property which allows the metals to be beaten into thin sheets with a hammer without breaking is called as malleability.

3. Sonorous. Ans. The metals that produce a sound on striking a hard surface are said to be sonorous.
4. Metalloids. Ans. Elements which show properties of both metals and non-metals are called as metalloids.

5. Anodising. Ans. The process used to make the aluminium surface resistant to corrosion and abrasion using electrolysis technique is called as anodizing.

6. Ionic bond. Ans. A chemical bond formed by transfer of electron(s) from one atom to another atom is called as ionic bond.

7. Ionic compound. Ans. Compounds containing ionic bonds are called as ionic compounds due to loss or gain of electrons.

8. Covalent bond. Ans. The chemical bond formed by sharing of electrons between two atoms is called as covalent bond.

9. Covalent compound. Ans. The chemical compound that is formed by mutual sharing of one or more pairs of electrons between the two combining atoms is called as covalent compound.

*10. Minerals. Ans. The naturally occurring compounds of metals along with other impurities are known as minerals.

*11. Ores. Ans. The minerals from which metals are extracted profitably and conveniently are called as ores.

*12. Gangue. Ans. The impurity of soil, sand and rocky material present in the ore is called as gangue.

*13. Metallurgy. Ans. The process used for extraction of metals in their pure form from their ores is called metallurgy.

14. Reactivity series of metals. Ans. The arrangement of metals in the decreasing order of their reactivity in the form of series is called the reactivity series of the metals.

15. Calcination. Ans. The process of converting carbonate ore into oxides by heating strongly in limited supply of air is called as calcination.

*16. Roasting. Ans. The process of converting sulphide ore into oxide by heating strongly in presence of excess air is called roasting.

17. Refining/Electrolytic refining. Ans. The process of purifying impure metals is called as refining.

18. Electroplating . Ans. It is a process in which an object made up of a conducting material is coated with a less active metal using electrolysis technique.

19. Corrosion. Ans. Corrosion is degradation of materials due to a reaction with its environment. OR The eating up of metals by the action of air, moisture or a chemical (such as acid) on their surface is called as corrosion.

20. Alloy. Ans. An alloy is an homogenous mixture of two or more metals or a metal and a non-metal in a definite proportion.

21. Galvanising. Ans. It is a process of giving a thin coating of zinc on iron or steel to protect it from corrosion.

22. Tinning. Ans. It is the process of giving a coating of tin, i.e., molten tin over other metal to prevent it from corrosion.

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